Handle split AnSiT messages for term.el (Bug#17231)

Check to see if there is an incomplete command at the end of
term-emulate-terminal's input string, and, if so, save it so the whole
command can be processed when the next string arrives.
* lisp/term.el (term-partial-ansi-terminal-message): New variable.
(term-mode): Make it buffer local.
(term-handle-ansi-terminal-messages): Prepend it to the received
message, and set it if a partial message was received.

Copyright-paperwork-exempt: yes

Do not merge to master, it will be solved differently there, see
"Switch term.el to lexical binding, and clean up code a bit".

1 files changed, 15 insertions, 0 deletions

diff --git a/lisp/term.el b/lisp/term.el
index ca83b4f8dcf..e51b7669e14 100644
--- a/lisp/term.el
+++ b/lisp/term.el
@@ -593,6 +593,9 @@ massage the input string, this is your hook.  This is called from
 the user command `term-send-input'.  `term-simple-send' just sends
 the string plus a newline.")
 
+(defvar term-partial-ansi-terminal-message nil
+  "Keep partial ansi terminal messages for future processing.")
+
 (defcustom term-eol-on-send t
   "Non-nil means go to the end of the line before sending input.
 See `term-send-input'."
@@ -1077,6 +1080,8 @@ Entry to this mode runs the hooks on `term-mode-hook'."
   (make-local-variable 'ange-ftp-default-password)
   (make-local-variable 'ange-ftp-generate-anonymous-password)
 
+  (make-local-variable 'term-partial-ansi-terminal-message)
+
   ;; You may want to have different scroll-back sizes -mm
   (make-local-variable 'term-buffer-maximum-size)
 
@@ -2702,6 +2707,11 @@ See `term-prompt-regexp'."
 ;;difference ;-) -mm
 
 (defun term-handle-ansi-terminal-messages (message)
+  ;; Handle stored partial message
+  (when term-partial-ansi-terminal-message
+    (setq message (concat term-partial-ansi-terminal-message message))
+    (setq term-partial-ansi-terminal-message nil))
+
   ;; Is there a command here?
   (while (string-match "\eAnSiT.+\n" message)
     ;; Extract the command code and the argument.
@@ -2754,6 +2764,11 @@ See `term-prompt-regexp'."
           (setq ange-ftp-default-user nil)
           (setq ange-ftp-default-password nil)
           (setq ange-ftp-generate-anonymous-password nil)))))
+  ;; If there is a partial message at the end of the string, store it
+  ;; for future use.
+  (when (string-match "\eAnSiT.+$" message)
+    (setq term-partial-ansi-terminal-message (match-string 0 message))
+    (setq message (replace-match "" t t message)))
   message)